**System Information**
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 1050 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 451.67
**Blender Version**
Broken: version: 2.91.0 Alpha, branch: master, commit date: 2020-08-25 19:28, hash: `rB396d39c6b904`
Worked: (newest version of Blender that worked as expected)
**Short description of error**
Mesh not unwrapping correctly even though seams are present.
**Exact steps for others to reproduce the error**
To reproduce this issue, select the pommel of the katana from the linked file and try to unwrap.
It doesn't work as expected on the thread on the handle as well.
Auto Unwrap works though. My guess is that the seams aren't being acknowledged by the unwrapper for some reason?
NB: Some parts of the katana don't seem to have this issue.{F8819249}